Posted On :

To account for the different conditions like for material strength, load etc. Different partial factors are used for material and load.

**Partial
safety factor**

To
account for the different conditions like for material strength, load etc.
Different partial factors are used for material and load. M indicate safety
factor for material & for load

Design
strength = Characteristic strength / rm

Design
Load = rf x Characteristic load

As per clause 36.4.2
page 68 of IS 456, ?_{m}=
1.5 for concrete and ?_{m}
=1.15 for steel. Similarly clause 36.4.1 page 68 of code gives ?_{f}
in table 18 for different values for different load combinations and different
limit states.

IS 456 - 2000 Recomendations

(i)Partial safety factors for materials to be multiplied with characteristic strength is given below.

(ii)The
code has suggested effective span to effective depth ratios as given below

(iii)The code has
suggested effective span to effective depth ratios as given below

Basic effective span to effective depth ratio (l/l)
basic

The above values are to be modified for (i) the type
and amount of tension steel (Fig 4 page 38 of T5456-2000)

(ii) The
amount of compression steel (Fig 5 page 39 of I5456-2000)

The type of beam ie flanged beams etc (Fig 6 page 39
of I5456 - 2000).

For slabs spanning in two directions, the l/d ratio
is given below.

For slabs spanning in two directions, the l/d ratio
is given below

Tags : Civil - Design of Reinforced Concrete Elements - Methods Of Design Of Concrete Structures

Last 30 days 267 views
Recent New Topics :